Essential Oils 101

Since we are in the “back-to-school” spirit, let’s do a little review on some of the basics of essential oils.

Quick Definitions from Modern Essentials

Essential Oils: Substances created inside aromatic plants that are both volatile (they evaporate) and oil soluble (they easily mix with oils and fats).

Aromatic: Referring to plants that have an aroma.

Topical Application: Placing an essential oil directly on the skin or other surface of the body.

Aromatic Application: Often called “aromatherapy,” aromatic application refers to inhaling an essential oil or its aroma.

Internal Application: Internalizing an essential oil, typically through the mouth.

Carrier Oil: A carrier oil refers to a vegetable oil, wax, fat, or other oil that an essential oil is mixed with. The carrier oil “carries” the essential oil and dilutes it so its effects can be spread over a large area.

Neat: Applying an essential oil by itself, without diluting it in a carrier oil.

Dilution: Mixing an essential oil in a carrier oil so its effects are not concentrated in one area.

Volatile: A substance that will evaporate when exposed to air is referred to as volatile. Volatile substances are typically light substances with small molecules.

Single Oil: A single oil is one type of oil (e.g., lemon, peppermint, lavender) by itself.

Oil Blend: An oil blend is a mixture of two or more single oils. Oils are typically blended to combine their individual properties or aromas.

Photosensitizing: Some essential oils (typically citrus oils) contain natural substances called furanocoumarins. Furanocoumarins can react with ultraviolet light to create substances that may cause hyperpigmentation or burning on the skin. While essential with furanocoumarins have many beneficial properties, care should be taken after applying these oils on the skin to protect the skin from direct, prolonged ultraviolet light exposure for 1–3 days.
(Modern Essentials, 6th Edition, inside front cover)

Essential Oil History 101

EgyptiansSince the beginning of time, aromatic plants have played an important role in medicine, religion, cosmetics, perfumes, courtship, and many other aspects of human life. Many ancient texts from all over the world discuss the use of aromatic herbs and the use of the aromatic constituents steeped or extracted from these herbs in oils, unguents, and salves for medicinal or other purposes.

While many people believe it was the smell of these aromatic plants that first attracted mankind to the use of aromatic plants for medicine, modern science is beginning to show that there is more to essential oils than just the smell.

Essential Oil Science 101

An essential oil is a group of chemical constituents that are distilled or extracted from all or part of an aromatic plant. Essential oils are volatile (meaning they can evaporate and be distilled) and oil soluble (meaning they will dissolve in or combine with oils or other lipids). The constituents that make up an essential oil are created by plants for immune defense, pollinator attraction, damaged tissue healing, and other metabolic purposes within the plant.


A single essential oil can actually be a complex mixture of hundreds of different chemical constituents, including various terpenes, esters, alcohols, aldehydes, ketones, phenols, oxides, and others. Many of these individual constituents have been shown in scientific research studies to demonstrate some remarkable properties––antibacterial, anti-cancerous, antioxidant, stress relieving, anti-inflammatory, and many, many more. Many constituents of essential oils also have the unique ability to penetrate into cells where they can assist in the cell’s natural functions and may even help combat viruses or other pathogens that have invaded inside a cell.

Because of these many different properties, essential oils are now often used aromatically, topically, and even internally to help support the body’s own natural healthy functions in many different ways.

If you are interested in learning more about the science behind essential oils, Modern Essentials contains more detailed, yet easy to understand, explanations about what essential oils are, the essential oil constituents, how essential oils are extracted, and how essentials oils interact with the body.

Therapeutic-Grade Essential Oils 101

Before using an essential oil, you should know that not all essential oils are created equally. Many oils are created as fragrance oils for use by the perfume industry or as flavoring oils for the food industry. Since these industries are primarily concerned with getting the smell of the oil at a low cost, many of these types of oils are extracted using harsh chemical solvents or are diluted with artificial chemicals that alter the properties of the oil and may even be harmful to the body. These types of oils should be avoided.

RoseOilBottleOnly essential oils that have been certified for their purity as a therapeutic-grade essential oil should ever be used for therapeutic purposes. Natural, pure, therapeutic-grade essential oils are only steam distilled (or pressed from the peel in the case of citrus oils) from plants that have been grown in the right way and in the right location—making them a powerful blend of therapeutic constituents in just the right proportions to help support the body’s own natural mechanisms to maintain health and well-being.

Oils and Water 101

You may have heard this saying by now: “Oil and water don’t mix!” If you have a reaction (such as redness or a burning sensation) to an essential oil, don’t run to the sink and try to use water. Here’s what Modern Essentials says to do:

OilWater“While pure, therapeutic-grade essential oils are generally safe and gentle to apply on the skin in the recommended amounts, a few oils such as oregano or cassia are very concentrated and may cause discomfort or heat when too much is applied directly on young or sensitive skin, or if they are accidentally placed into the eyes or other sensitive areas of the body. If this happens, ALWAYS use a vegetable oil such as fractionated coconut oil or olive oil to dilute the essential oil and relieve discomfort. NEVER use water to dilute the essential oil. Since water and oil don’t mix, placing water over the essential oil can actually drive the oil deeper into the tissue, increasing the feeling of discomfort. Placing a carrier oil over the essential oil will cause the essential oil to mix with and be dispersed within the carrier oil, helping to relieve discomfort” (Modern Essentials, 6th Edition, inside front cover).

For more information on any of the above topics, please refer to the Science & Application section in Modern Essentials.

Source: Modern Essentials, 6th Edition

Have you learned anything new from this little lesson about essential oils? Is there an essential oil topic you would like us to expound on? We would love your feedback! Please comment below.

See Modern Essentials: How Essential Oils Interact with the Body

Have you ever wondered how essential oils interact with your body? The latest edition of the Modern Essentials book includes a section explaining how essential oils produce their therapeutic effects. The most recent research on essential oils is included in this section to help you understand how to better use essential oils based on their interactions with your proteins, organs, and body systems. Understanding how an essential oil interacts with the body is crucial for interpreting its therapeutic effects and developing a personal holistic health regime.

Systemic and Localized Effects

Essential oils are able to affect the body in two main ways, depending on the chemical constituents composing the essential oil. For example, the figure below shows the possible effects of applying an essential oil topically. Depending on the chemical constituents of the oil, topical application may result in localized effects or systemic effects.

Localized effects will only produce therapeutic properties to the specific area where the essential oil was applied. On the other hand, systemic effects occur when the essential oil constituents cross the epidermal layer of the skin, are absorbed into the capillaries of the tissues below, and are circulated throughout the body. Researchers have found that some essential oil constituents always produce systemic effects because the chemical constituents are molecularly small and have the ability to permeate cell membranes (Kohlert et al., 2000).

Both effects are useful. For example, a localized effect is desirable when using an essential oil to treat a rash or acne. Furthermore, systemic effects are desirable when treating a body wide health issue, such as a bacterial infection or cardiovascular problem. Continue reading